Tsunoda was labelled a fast but slightly inconsistent hothead upon his F1 arrival in 2021 at the tender age of 20, going viral because of his expletive-laden radio messages.
But with it being easier to calm a fast driver down than it is to make a consistently average driver faster, both the team and Tsunoda's Honda backers kept supporting him as he matured into a tidy, well-rounded racer. Aboard an uncompetitive car, he delivered his best season to date in 2023, proving right outgoing team boss Franz Tost's adage that a young driver needs three seasons to properly adjust to F1.
As the team morphed from AlphaTauri into RB or VCARB, the now 24-year-old appears to have found another level that his much more experienced team-mate Daniel Ricciardo, an eight-time grand prix winner, has found hard to match.
As RB proved more competitive than last year, Tsunoda has so far consistently reached Q3 and scored points on five occasions, to the point where his off-track excursion in a wet-to-dry Canadian Grand Prix is now considered out of character.
But despite ramping up his performance levels, there has never appeared to be any serious momentum to promote Tsunoda to Red Bull's main team, with Ricciardo brought back to RB to be an insurance policy if Sergio Perez failed to meet requirements.
And with Perez re-signing on a two-year deal, despite a tough recent spell in Imola, Monaco and Canada, it seems like Tsunoda's career is stalling for reasons beyond his control.
Red Bull's strong man Christian Horner appears unconvinced Tsunoda can be the calm and harmonious presence alongside Max Verstappen that he wants, although team advisor Helmut Marko has kept the door open for a promotion in the future, suggesting Tsunoda clicked into gear a little too late to be considered for 2025.
"He has to continue to perform like he does now. Let’s see what the future brings then," Marko told Autosport. "His development is really good, although it came a little bit later than we expected, but he is now a top driver I would say."
"This is the first season in which Yuki is consistently fast and he is controlling his emotions, which was his biggest problem before.
"To be fair to him, he had always flashes of speed, but this year besides the China race he is consistently fast. Of course, it is changing his profile."
Tsunoda understandably looked a bit frustrated when asked to respond to Perez's contract renewal, a day before his staying put at RB was officially announced.
"Obviously, I'm already committed to Red Bull a lot and hopefully I can have a bit more commitment from them," he said.
"There's an ongoing discussion and I want to make sure first of all we're on the same page with Red Bull after that we'll see. But I'm happy with RB.
"Even these two years [Perez] has to still perform and in this kind of environment, anything can happen.
"So congratulations to him, but for me, I just keep focusing on what I'm doing and just proving myself.
"Hopefully, Red Bull will see more of my progress and my potential performance and maybe [it] can change in the future."
For 2025 Tsunoda's fate was in Red Bull's hands, with it taking up an existing option to keep him on the roster.
His options elsewhere looked limited too. He was mooted as being on Audi's shortlist should it not secure Carlos Sainz or its other targets.
He was also linked to Aston Martin purely through his Honda link, with the Japanese manufacturer becoming Aston's works engine partner in 2026. But that would depend on Lance Stroll deciding to call time on his F1 career, which looks very unlikely right now.
But with RB the standout performer in 2024's midfield, nipping on the heels and even overtaking Aston Martin on certain circuits, perhaps Tsunoda's best move was to stay where he is all along.
Backed by new sponsors Visa and CashApp, the Anglo-Italian team is looking to evolve into more than just Red Bull's B-team in both identity and performance.
It has tweaked its driver philosophy, now pairing an experienced driver with an up-and-coming talent rather than being a pure junior team. And with Daniel Ricciardo yet to deliver on a consistent basis, it appears Tsunoda has now moved from the second to the first category and become that experienced pair of hands the squad is happy to build around.
Speaking to Autosport, team principal Laurent Mekies said keeping hold of Tsunoda for a fifth season in 2025 was "key for the project" the former Ferrari man is building.
"He has been doing a phenomenal step this year, which went well beyond our expectations. We were expecting a step but in a fourth year doing such a step change is very impressive, both in terms of pace and outside of the car.
"[His progress] is 360 degrees. It's not just maturity. The pure speed takes steps, the dialogue with the engineers takes a step, the calmness takes a step.
"It is a superb feeling to witness that and it's also our responsibility to ask ourselves the question: 'How many steps like that does he still have inside him?'
"We have to make sure that we create the environment for him to develop them and that's our task for the next months and next year. It has become crucial for the project and natural to continue with him."
Mekies said he understood any frustrations at being snubbed by Red Bull, and admitted that if Tsunoda continues progressing at his current rate, he might be "difficult to ignore" for Red Bull or rival teams next year.
"Look, he's a Red Bull driver, so he needs to have the ambition to go to Red Bull Racing," Mekies added.
"He has it, and he's doing everything he can to prove that. He's ambitious, we are ambitious. We are pushing each other.
"If he does another step like that next year, he will be difficult to ignore for anyone."
But until that day comes, Red Bull's loss is RB's gain. Red Bull might not fully trust Tsunoda yet, but his current team certainly does.
